1. Field of the Invention
The present invention relates to an accessory unit detachably attached to an eyepiece portion of a camera body and a camera system including the accessory unit and the camera body.
2. Description of the Related Art
Conventionally, a finder eyecup of the camera is attached to an eyepiece frame of the camera. The eyecup is used highly frequently to prevent interruption of shooting by incidence of the outside light when a user looks through the finder.
This type of the finder eyecup is discussed, for example, in Japanese Utility Model Application Laid-Open Nos. 2-89435 and 4-130932, and Japanese Patent Application Laid-Open No. 9-222569.
According to Japanese Utility Model Application Laid-Open No. 2-89435, an eyecup claw provided in the eyecup is fitted into an eyepiece frame groove formed in the eyepiece frame of the camera body, so that the eyecup claw is elastically deformed and mounted on the eyepiece frame. A claw portion formed in the eyecup claw is engaged with a step portion formed in the eyepiece frame, so that the eyecup cannot easily come off. Japanese Utility Model Application Laid-Open No. 2-89435 discusses an improved type in which the eyecup is provided with an operating portion to allow the eyecup claw to pivot in the opening direction so that the eyecup can be easily detached by the user.
Japanese Utility Model Application Laid-Open No. 4-130932 discusses a configuration in which an elastic member such as a rubber member is almost integrated to the camera body in the periphery of the eyepiece frame provided in the camera body.
Japanese Patent Application Laid-Open No. 9-222569 discusses a configuration in which each of the eyepiece frame and the eyecup provided in the camera body is threaded, and the eyecup is attached by screwing into the eyepiece frame.
Meantime, the eyepiece frame is often used as an attaching position of various accessories in addition to the eyecup, for example, an eyepiece cap and a magnifier. Hence, when these accessories are attached, the eyecup that is highly frequently used needs to be detached in each case, and therefore, the eyecup is useful if it is easily detachable. On the other hand, it is not desirable that the eyecup is unintentionally detached when the user takes the camera in and out from a camera bag.
The eyecup discussed in Japanese Utility Model Application Laid-Open No. 2-89435 is designed such that the claw portion formed in the eyecup claw is engaged with the step portion formed in the groove portion of the eyepiece frame so that the eyecup cannot be easily detached. However, when the user intentionally detaches the eyecup, a user needs to detach the eyecup by elastically deforming the eyecup while the eyecup is climbing over the step portion. Accordingly, when an amount of the engagement with the step portion is increased, a problem arises that the eyecup is difficult to be detached. On the contrary, when the amount of the engagement is decreased to improve the detachability, the eyecup can be unintentionally detached. To solve these problems, an improved eyecup described above is provided with the operating portion to enable the eyecup claw to pivot. That is, when the user intentionally detaches the eyecup, the user manipulates the operating portion, and the user detaches the eyecup after the claw portion formed in the eyecup claw comes off from the step portion formed in the groove of the eyepiece frame. Thus, the detachment can be easily performed.
In the eyecup discussed in Japanese Utility Model Application Laid-Open No. 4-130932, an elastic member such as a rubber member is directly integrated to the camera body at the peripheral surface of the eyepiece frame, and the eyecup is difficult to be detached without the user's operation.
In the eyecup discussed in Japanese Patent Application Laid-Open No. 9-222569, the eyepiece portion and the eyecup are fixed by a screw, and a problem that the eyecup unintentionally comes off can be avoided.
However, the conventional eyecups have the following problems.
In Japanese Utility Model Application Laid-Open No. 2-89435, it is only the elasticity of the eyecup claw that exerts a force in the engaging direction of the claw portion and the step portion. Hence, when a larger force than the elasticity acts, the eyecup claw opens up and the claw portion comes off from the step portion. As a result, the problem that the eyecup unintentionally comes off cannot be completely avoided.
In Japanese Utility Model Application Laid-Open No. 4-130932, when another accessory is attached to the eyepiece frame, a part of the elastic member such as a rubber member needs to be elastically deformed, and problem may arise that the operation becomes troublesome or the elastic member is damaged. Also, during the assembly of the camera, the elastic member needs to be elastically deformed and attached to the eyepiece frame, so that the assembly of the camera cannot be easily performed and the elastic member can be damaged.
In Japanese Patent Application Laid-Open No. 9-222569, when another accessory is attached, the eyecup needs to be rotated and detached, and there is a problem that the operability is low since the eyecup cannot be quickly detached. Because each of the eyepiece portion and the eyecup needs to be threaded, the cost is increased.